Our objective is to use a canine lung cancer model for interdisciplinary clinically relevant surgical research on bronchogenic carcinoma. Existing small animal models neither have cancers like those in man, nor are they practical for innovative diagnositc and therapeutic trials. We have induced sharply localized, endobronchial, predominantly squamous pre-malignant changes in dogs using recurrent transbronchoscopic submucosal injections and/or topical applications of the proven carcinogens 3,4-benzo(a)-pyrene and/or N-methyl-N-nitrosourea. Current aims are: 1. To complete the definition of the model to permit following the transition from benignancy to malignancy with predictability; 2. To simplify carcinogenesis; 3. To evaluate multiple site synchronous carcinogenesis; 4. To evaluate ultraviolet (UV) fluorescent bronchoscopy for detecting early or occult lung cancers pre-clinically; 5. To characterize the immunologic properties of induced lung cancers in dogs. We plan to continue following the existing colony of dogs with the addition of ultrastructural observations. We wish to decrease the expense of carcinogenesis by investigating sustained release submucosal endobronchial carcinogen implants in geriatric as well as in young dogs. Inbred HL-A typed dogs with potentially transplantable tumors shall be used for multiple site synchronous carcinogenesis experiments. UV-bronchoscopy shall be tested on pre-neoplastic, neoplastic and control sites in the bronchi to detect the in vivo concentration of fluorescent hematopophyrin derivative at these sites. Using stored frozen serum specimens from dogs now undergoing carcinogenesis, and specimens from new dogs to undergo carcinogenesis, the humaoral antibody response and cell mediated immunologic response of bronchial carcinogenesis shall be studied. We plan in the future to use the canine model to supplement studies upon lung cancer in humans.